1. Field of the Invention
The present invention relates to a core slider for a rigid magnetic disk drive consisting of a slider body having air bearing portions, and a core chip which has an information writing/reading magnetic gap and which is integrally bonded to the slider body. The invention also relates to a method of producing such a core slider.
2. Discussion of the Prior Art
A so-called composite type core slider is known as an air-bearing or flying type core slider for a rigid disk drive. The composite type core slider consists of a slider body having air bearing portions, and a core chip having a magnetic gap for writing or reading information on or from a magnetic memory disk. The slider body and the core chip are prepared as separate members, and are integrally bonded together. As compared with a monolithic type core slider, this composite type core slider has a smaller core thickness and accordingly lower inductance, and exhibits better high-frequency operating characteristics. The composite type core slider has an additional advantage that crosstalk can be reduced by forming the track portion such that the side faces of the track portion are substantially perpendicular or normal to the sliding surface on which a magnetic disk slides in operation.
On the other hand, the composite type core slider suffers from easy cracking of the bonding glass and easy distortion, if the slider body and the core chip have a difference in the coefficient of thermal expansion. In this respect, it is necessary to minimize the difference in the thermal expansion coefficient of the slider body and core chip. If the slider body and the core chip are formed of a same material, however, there is an undesirable tendency that a magnetic flux leaks from the core chip toward the slider body, causing the inferior information writing/reading efficiency.
To avoid deterioration of the magnetic properties of the known composite type core slider due to the magnetic flux leakage, the slider body is generally formed principally of a non-magnetic ceramic material such as CaTiO.sub.3, whose coefficient of thermal expansion is almost equal to that of the ferrite of the core chip.
The conventional core slider whose slider body is formed of a non-magnetic ceramic material, particularly, the widely used core slider whose major component is CaTiO.sub.3 has a high coefficient of friction with respect to the magnetic disk, and therefore has a high tendency of damaging the magnetic disk due to the frictional contact, whereby the slider body is likely to be damaged.